Using those formulas:
Hornetneedle would give: 5+((150-180)*1.5/180) = 4.75 TP per hit
Garuda's Dagger would give: 5+((183-180)*6.5/270) = 5.07 TP per hit.
The difference is pretty insignificant but the overall side bonuses of Garuda's Dagger and static 5 TP per hit win me over imo. But it all comes down to a matter of preference in the end.